Informace o publikaci

Butterfly swimming technique variations during an exhaustive swim exercise



Rok publikování 2017
Druh Článek ve sborníku
Konference Proceedings of the 11th International Conference on Kinanthropology
Fakulta / Pracoviště MU

Fakulta sportovních studií

Klíčová slova speedometry; fatigue; lactate test; stroke technique
Popis Purpose: Fatigue significantly influences not only physiological parameters during swimming, but also the technique of swimming stroke. Fatigue, therefore, affects also swimmers performance. This study aims to find out to what extent fatigue influences the technical execution of the butterfly stroke with and without breathing. Method:This work is structured as a case study. The participant was one of the best Czech and European swimmers, a 50 m butterfly Czech record holder. The swimmer performed a standardized lactate test - 8 x 50 metres butterfly swim.In selected moments his heart frequency was measured using a sport tester Polar and a blood sample was taken for lactate level test using Lactate scout+ device. A speedometer “Swim-Speedo-Meter” fixed on the belt and a video record was used for the stroke technique analysis. Temporal, spatial and speed characteristics were evaluated from the acquired curve of the swimmers speed. Results: Maximum heart frequency (172 bpm) as well as blood lactate level (14.2 mmol·l-1 ) was reached after fifth 50m track. There was a huge increase in stroke frequency with increasing fatigue. This fact resulted in the decrease in stroke duration from initial 1.37 s to 1.09 s in stroke with breathing and from 1.29 s to 1.06 s in a stroke without breathing. Significant changes during the transition phase from “insweep” to “upsweep” were observed, with a huge decrease in speed. Furthermore, accumulated fatigue caused that the speed developed during “insweep” phase was smaller in the second part of lactate test compared to the previous parts. These major differences in technique negatively influence stroke effectiveness.Conclusion: The core importance lies in between relations of measured variables that show changes of butterfly stroke technique as swimmer fatigue increased. We recommend to focus on strength and dynamic preparation during training, mainly leg movement during the second kick. We also recommend regular speedometer measurements which can help control changes in technique causedby factors such as fatigue, injury, different period of training annual cycle, etc.